Public water system · WY5680082
ActiveYnp- Madison Junction Water System
At a glance
Ynp- Madison Junction Water System (PWSID WY5680082) is an active transient non-community water system in Teton County, Wyoming. It reports serving 1,205 people through 122 service connections. Its primary water source is groundwater under influence of surface water, and EPA lists it as owned by the federal government. EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,205
Service connections
122
Primary source
GU
Groundwater under influence of surface water
System type
TNCWS
Transient non-community water system
System record
How does Ynp- Madison Junction Water System compare with other water systems in Teton County?
By EPA's size categories, Ynp- Madison Junction Water System is a small system (501 to 3,300 people). Teton County has 112 active public water systems. Its population served is about 73% above the county average of 697 people per system, and accounts for 1.5% of the 78,057 people reported by systems filed under the county. Across Wyoming, the 775 active systems average 838 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Ynp- Madison Junction Water System is about 8.4 times that figure.
What does “transient non-community water system” mean?
A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. Wyoming has 352 active transient non-community water systems, 45% of the state's 775 active systems. Groundwater under the influence of surface water is well or spring water that the regulator has found to be affected by nearby surface water, so it is regulated under the surface-water treatment rules. 24 Wyoming systems (3.1%) list groundwater under influence of surface water as their primary source.
Who owns and regulates Ynp- Madison Junction Water System?
EPA lists Ynp- Madison Junction Water System as owned by the federal government. The WY state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 32 of the 112 active systems in Teton County (29%) are also owned by the federal government.
Does Ynp- Madison Junction Water System have drinking water violations?
EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in October 2024. The violations listed here began between October 1993 and October 2024. By type: 4 monitoring and reporting, 2 monitoring, 2 required treatment not met and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Surface Water Treatment Rule (4 of them). EPA lists 8 as resolved and 1 as archived. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2024-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-10-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2024-06-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2024-05-01 | Required treatment not metTreatment Technique Startup Procedures (RTCR) · code 2D | Revised Total Coliform Rulecode 8000 | Yes | Resolved |
| 2023-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-10-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2022-01-10 | Required treatment not metFailure to Filter (SWTR) · code 42 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
| 2010-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
All 9 violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Ynp- Madison Junction Water System: frequently asked questions
Who runs Ynp- Madison Junction Water System?
Ynp- Madison Junction Water System (PWSID WY5680082) is a transient non-community water system owned by the federal government. It is regulated by the WY state drinking water program.
How many people does Ynp- Madison Junction Water System serve?
Ynp- Madison Junction Water System reports serving 1,205 people through 122 service connections in Teton County, Wyoming.
Where does Ynp- Madison Junction Water System get its water?
EPA SDWIS lists this system's primary water source as groundwater under influence of surface water. Groundwater under the influence of surface water is well or spring water that the regulator has found to be affected by nearby surface water, so it is regulated under the surface-water treatment rules.
Does Ynp- Madison Junction Water System have any drinking water violations?
EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in October 2024. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Ynp- Madison Junction Water System's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in October 2024. For current results, consult EPA ECHO, or the WY state drinking water program.
Where can I find Ynp- Madison Junction Water System's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Ynp- Madison Junction Water System is a transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Teton County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Jackson, Town of | Teton | 24,760 | Community | Groundwater |
| Ynp-Old Faithful | Teton | 7,675 | Community | Surface water |
| Ynp - Lake Village | Teton | 5,925 | Community | Groundwater under influence of surface water |
| Gtnp-Colter Bay Village | Teton | 4,514 | Community | Groundwater |
| Ynp-Grant Village | Teton | 3,513 | Transient non-community | Surface water |
| Grand Targhee Resort | Teton | 2,500 | Non-transient non-community | Groundwater |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Ynp- Madison Junction Water System, PWSID WY5680082, Wyoming”, https://aquacensus.com/water-systems/wyoming/ynp-madison-junction-water-system-wy5680082 (data as of October 1, 2026).